There will be some main volume setting at which you would not be able to achieve the 75db by just adjusting the trim levels. I think I calibrated mine at the -10 setting which means most of my trim setting are in the -2 to +3 range. Everyones would be different.

The gain structure of the 950 is optimized for calibrating with the volume control at around "0" and for SPL of 75db. Going beyond these norms can either cause degradation of the signal to noise ratio or lack of enough range in the adjustment trims to achieve a balance between speakers.

mhua,

I purchased a 950 last year and thought the hiss issue was resolved. The hiss was audible 8 feet away on all inputs (but especially with analog) with the volume set at 0 dB. Rather than send it back for another one I returned it. My old Denon receiver was completely quiet. My Aragon Stage One is also extremely quiet. You may need to return the unit and try again.

Now that is hard to believe with a properly calibrated system. My speakers are 106db/watt efficient and I can't hear hiss from that distance. I seriously doubt your speakers are more efficient than mine.

There are only two variables that would make the hiss more or less audible with a properly functioning 950:

1) The efficiency of the speakers. This is assuming there is nothing in the speaker's design which boosts the high frequencies beyond what would be flat response.

2) Proper calibration. If the calibration is improperly performed so that the 950 is providing more gain than is necessary for 75db SPL at the listening position using the internal test tone, then hiss will be audible.

Soundhound,

I do respect your experience in the field and your experience with audio equipment, and you don't have to believe. I calibrated my system with a radio shack meter, used expensive interconnects and speaker cables, ran a dedicated AC line just for the audio, and a Monster 3600 filter for the whole system. My point is that I believe the unit probably was defective and sent it back rather than try a new one. I believe Outlaw would have exchanged it, no questions asked. The original post from mhua asked if the issue was still a problem and for me it was. Outlaw is a great company. This forum can make it appear that there are more quality issues than there really are because it is open. roblinds said it best. There are different kinds of people out there with their own agendas. I don't have an agenda. But, I stand by my original statement. Once I exchanged the 950 with the Aragon, the hiss was gone. The problem has not completely gone away.

tgrisham, thank you sharing your experience with the 950. The hiss issue is not severe to me in normal listening condition, at 0dB the hiss with analog inputs is audible at around 2 feet way from the speakers, it would start to become more annoying while the volume is going higher from there. At +10dB, I can hear the hiss from the listening position (8 feet away). There is no hiss at all for me with digital inputs.

Based on what I heard from many of the 950 owners at this forum, this level of hiss seems well acceptable. Other than this issue, I am pretty happy with the 950 performance after my two weeks' ownership. Will continue my evaluation with all different music I have for another two weeks, and see if anything would come up to change my mind.

Your Aragon Stage One is a great pre/pro, continue to enjoy it!

Recently I did a little test. During the viewing of a movie, I pulled out the good ol’ RS analog meter and set it up at the listening position. I then cranked up the volume on the 950 so that the SPL was swinging just past +116 dB during heavy explosive rumbling. Granted, most of that SPL was coming from the subs, but it was in balance with the rest of the audio spectrum. I then stopped the DVD and selected a non-digital source. I approached the right front speaker ear first and noted that the point at which I could discern hiss was less than twelve inches from a tweeter.

remark – I think that if I had used enough gain to make the hiss audible at my listening position and then began playback of program material, I would have to report: “I hear a high pitched ringing at my listening position, even when my HT gear is powered down completely!”

First off, any hiss that I can detect at any position, at any level, and from any speaker, I can attribute to another device in my system other than the 950. (It's usually my analogue equalizers that are the culprit.) The 950 is simply dead quiet.

Since this thread has also touched on calibration (as have others in the Saloon) I've got a bit of a nagging question to ask - especially of Soundhound since I'll use his system as part of the question.

I run fairly efficient speakers across the front - 96dB or so. That's 10dB less than what Soundhound has posted - and probably 5-8dB more than your "average" speaker.

I get an SPL reading of 85dB in my system when I set my 950 to -10dB AND with the front L/R calibration set at -5dB. Without individual gain controls on my amps (well, all but one) how the heck would I ever hope to calibrate for 85dB at a "0" setting" on the 950 - let alone 75dB? There just ain't much more "calibration" level left in the 950 to back off on. If I had Soundhound's speakers I'd be 10dB further away.

I can only conclude that it would take a combination of i) lower efficiency speakers and/or ii) lower set amplifier gain and/or iii) actual power amp gain controls, to be able to hit either 75 or 85dB at a "0" setting on the 950.

Soundhound: can you crank the gain down on your amps to hit these targets? If not, how do you do it?

In any case, hitting 85dB at a "-10" volume setting on my 950 leaves me way more than enough left at the top end (anything beyond -5 to 0 is just way too much for these old ears) and plenty of room to reduce the level to clean background "reading" levels.

Regards.

Jeff Mackwood

Jeff:

I have installed input level controls on my amps that didn't originally have them except for the amp that drives my high frequency horns. On that amp, I lowered the gain to less than unity (an actual voltage loss!) by replacing the input tube with one which has lower gain.

When I calibrate the 950, I set it's trims at "0" for all channels and the main volume at "0". I then do all the level adjustment with the volume controls on the power amplifiers.

If I had to rely on the trim settings in the 950 with my efficient speakers, I would never be able to get anywhere close to 75db.

Thanks Soundhound.

You confirmed what I suspected - and that I was not missing something else really obvious that the rest of the world knew - and I didn't. (Hate when that happens )

Regards.

Jeff Mackwood